Safety device for containers for explosives, particularly explosive gases



July 18, 1933.

H. GROHMANN SAFETY DEVICE FOR CONTAINERS FOR EXPLOSIVES, PARTICULARLYEXPLOSIVE GASES Filed May 5, 1930 /n venfor:

Patented July 18, 1933 misstemes;

HANS GROEEIANN QF I-IIBSGIEIFELDS, GERMANY SAFETY DEVICE FOR CONTAINERSFOR EXPLOSIVES, PARTICULARLY EXPLOSIVE' GASES Application filed May 5,1930, Serial No.

This invention relates to a safety device for containers charged withcombustible (explosive) substances, so that in the event of an explosionoccurring this shall not extend to the inside of the container. 7

Inthe device according to this invention, there is interposed in thepath of the combustible (explosive) substance or gas, a safety shieldconsisting of a quantity of some ma- 1o terial such as sand, quartz,metal or other material of such consistency thatthe recoil caused by anexplosion will compress the heap, so that firstly it acts as anobstacle,"and secondly by absorbing and using up consid- 5 erablequantities of heat in the form of mechanical energy, it prevents thepropagation of the explosion.

It is desirable to select for the composition of the compressible heap,materials which by undergoing physical or chemical changes can absorbstill further quantities of heat.

According to the present invention, the heap is placed in front of thecross section of the pipe or vessel containing the explosive substancesthat it is desired to protect, and

it rests upon a plate perforated with small apertures and capable ofresisting the bending strain caused by the high pressures due to anexplosion, in such a manner that without preventing the free passageunder normal conditions of the combustible materials (gases), it will,in the event of an explosion,

be mechanically compressed by the resulting shock, and will possiblyalso undergo a physical or chemical change, with the result that themechanical compression will either wholly or for the greater part closeup the crosssection to be secured and prevent the gas from passingthrough it, whilst at the same time a portion of the heat emitted by theexplosion is absorbed in consequence of physical or chemical action uponthe compressed heap. In this way not only is the container or pipe whichit is desired to secure protected against the shock of the explosionwave itself, but it is also protected against the heat which otherwisewould be conveyed by conductivity.

The physical absorption of that part of the heat of the explosion whichis not ab- 449361, and in Germany July 24, 19 29.

sorbed by the work of deformation, may, for example be brought about inadequate degree by usingjas the filling substance a heap of particles ofa metal in which the product of specific gravity, specific heat and heatconductivity is as large as possible, or alternatively by using a heapof particles of a substance that melts readily, for example, finelybroken up sulphur, flour of sulphur, which under the action of thepressure caused by an explosion, whilst absorbing a certain amount ofmechanical energy will become compressed, simultaneously beginning tofuse under the action of the heat of the explosion wave, therebyabsorbing a large part of the o5 explosion in the form of fusing heat.The absorption of a part of the explosion heat by means partly physicaland partly chemical is also feasible by the choice of a suitable fillingsubstance, for example, if we se '10 lect ammonia alum, a saltcontaining up to 47% of water in the form of water of crystallization,with the result that the water in this substance is caused by thetemperaure of the explosion heat to evaporate, thereby abso'rbing aportion of the explosion heat. In the device forming the subject of thisapplication, the heat is held as a result of the constitution of thefilling substance forming the interposed heap, either by conduction,fusso ing, evaporation of moisture, or some other means, and partly bythe simultaneous compression (deformation) of the fillingsubstance-itself.- This compression absorbs heat by transforming it intomechanical energy and brings about at the same time a more intimatecontact between the hot explosion gases and the filling substance,thereby reacting favourably upon the interchangev of heat and finallyclosing up the passage against any further penetration of the explosionwave.

The accompanying drawing is partly an elevation and partly a verticalsection of a container and provided with a safety device constructed andarranged in accordance with this invention.

In the embodiment of my invention here shown, a nipple N is'screwedgas-tight into the container to be protected. This nipple is providedwith a screwed-on valve V and with the safety cartridge Q, consisting ofa tube screwed on to the lower end of the nipple N, with a rigidperforated bottom P, and filled with a heap of some suitable substancesuch as aluminium filings, sand quartz or the like, which will beCompressed by the force of the explosion, thereby completely closing upthe apertures in the bottom P.

On an explosion wave passing from outsidethrough the nipple N into thecartridge, the first thing to happen is that the heaped mate rial in thecartridge will be compressed. If anyhotexplosiongasesdomanagetopenetratethrough the apertures in the bottom P, they must first find their waytherefrom into the narrow ring shaped space between the covering of thecartridge Q and a metal sleeve M which surrounds it concentrically. Thisexternal sleeve surface M is however completely surrounded by thecooling substance so that any small portion of the residue of the hotgases that may have found its way through the apertures. in the bottom Pof the cartridge Q, and into the ring-shaped space, will by that time begreatlycooled down, and it is only in this cooled state that it can passfrom the upper edge of the ringspace through the closing-sieve T and soreach the interior of the cylinder. On emerging from the sieve T at theupper end of the cartridge these residual explosion gases will strikethe metal surface of the container charged with the combustiblesubstance and will thereby undergo a further energetic cooling process.

What is claimedr 4 1. A safety device for explosive gases or containersof explosive charges, comprising ing from an explosion and to therebycut off the passage of the explosion gases to the container, andan'outer shell around and spaced from the cartridge shell, so that anarrow space is formed between the two closely arranged surfaces of saidshells so that the residue of the hot explosion gases which may passthrough the loose material must pass through this narrow space before itcan enter the container.

2. Safety device according to claim 1, characterized by the fact thatthe ring-space surrounds-a cartridge constructed in the shape of atubeand containing the heaped substance, so that the hot explosion gasestraverse the heaped material within the cartridge in onedirection andthe ring-space in the opposite direction.

Safety device according to claim 1, characterized by the fact that inorder to protect thecontainer chargedwi-th explosive gases, the. latteris fitted with a screw-on nipple together with a tube-shaped extensionscrewed on to the nipple reaching into the interior of the container andcarrying the safety device.

HANS GR OHMANN.

